Anti-tuberculous therapy for maintenance of remission in Crohn's disease

Background: There have been a number of studies with conflicting results which have examined the effect of anti-tuberculous therapy in Crohn's disease. A meta-analysis was performed to evaluate the use of anti-tuberculous therapy for the maintenance of remission in Crohn's disease. Objectives: To evaluate the effects of anti-tuberculous therapy for the maintenance of remission in patients with Crohn's disease. Search methods: We searched the Inflammatory Bowel Disease Trials Register, the Cochrane Controlled Trials Register and MEDLINE from 1966 to 1998 (supplemented by a manual search of Index Medicus from 1966 to 1994). We also searched for abstracts in Gut, Gastroenterology, and The American Journal of Gastroenterology from 1990 to 1996. Date of most recent search: August 1998. Selection criteria: Randomized trials of anti-tuberculous therapy in patients with Crohn's disease. Data collection and analysis: Data on the number of patients maintaining remission for each treatment group were abstracted. These data were pooled to yield Mantel-Haenszel odds ratios and numbers needed to treat for maintenance of remission in treated versus control groups. Main results: A total of seven randomized trials which included 355 patients were identified. Two trials used anti-tuberculous therapy (clofazimine or clofazimine, rafmpin, ethambutol, and dapsone) in combination with corticosteroids to induce remission. Maintenance therapy consisted of the anti-tuberculous agents without corticosteroids. Control patients received corticosteroids to induce remission but no anti-tuberculous therapy. The analysis of all seven trials yielded an odds ratio for maintenance of remission of 1.36 (95% CI 0.87-2.13). Removing the two studies that were published as abstracts did not significantly affect this result: the pooled odds ratio was 1.14 (95% CI 0.71-1.83). The two trials reported as abstracts were excluded from subgroup analyses because they did not include any information on adjunct therapy. Subgroup analysis of the two trials which used steroids to induce remission yielded an odds ratio for maintenance of remission of 3.37 (95% CI 1.38-8.24). The number needed to treat was three. However, these two trials included only 89 patients, and the results should be interpreted with caution. The remaining three trials compared the combination of anti-tuberculous therapy and 'standard therapy' with 'standard therapy alone'. The pooled odds ratio was 0.70 (95% CI 0.39-1.25). Authors' conclusions: Anti-tuberculous therapy may be effective in maintaining remission in patients with Crohn's disease when remission has been induced with corticosteroids combined with anti-tuberculous therapy. However, the results which support this conclusion come from a subgroup of only two trials with small numbers of patients and should be interpreted with caution. Use of this therapy cannot be recommended on the basis of this evidence.